Safety toe iron for safety ski bindings



Oct. 15, 1968 L. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS I Filed April 28, 1965 17 Sheets-Sheet 1 INVENTORS Ludwig Berchiold, I Albert Schusfer 'mawzgmzw' ATTORNEYS 1963 L. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28, 1955 17 Sheets-Sheet 2 Fig.4

Oct. 15, 1968 L. BERCHTOLD ETAL 3,405,951

1 SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed .April 28, 1956 17 Sheets-Sheet 5 Fig. 5

Oct. 15, 1968 BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28, 1965 17 Sheets-Sheet 4 Fig. 7 3

36 I6 Fig.6

Oct. 15, 1968 L. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS l7 Sheets-Sheet 5 Filed April 28, 1955 Fig. 12

' 1953 L. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS.

Filed April 28, 1966 17 Sheets-Sheet 6 Fig. 13

Fig. 14

Fig. 15 V 56 1968 L. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS l7 Sheets-Sheet 7 Filed April 28,

Fig. 76

Fig. 17

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Oct. 15, 1968 L. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28. 1965 17 Sheets-Sheet 8 Fig. 1d

Oct. 15,1968 L. BERCHTOLD ETAL 5 SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28. 1966 17 Sheets-Sheet 9 20 Fig. 21

Oct. 15, 1968 j L.-BERCHTOLD ETAL 3, 7 SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28. 1965 1'7 Sheets-Sheet 1o Fig.2.? v

Fig.24

Q r J Oct. 15, 1968 L. BERCHTOLD ET AL.

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28, 1956 17' Sheets-Sheet 11 PRESTRAIN Oct. 15, 1968 1.. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28, 1965 1'7 Sheets-Sheet 12 T Fig. 26 a.

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' 5 22 2'' 20 25 vp 1a 2 4 P? 1 1 42 Oct. 15, 1968 BERCH TOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28. 1956 17 Shets-Sheet-IJS Fig. 26

Oct. 15, 1968 L. BERCHTOLD ETAL. 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28, 1955 17 Sheets-Sheet l4 Oct. 15, 1968 1.. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS l7 Sheets-Sheet 15 Filed Apr-i1 28,

Fig. 32

Oct. 15, 1968 L. BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS Filed April 28, 1966 1'7 Sheets-Sheet 16 1968 L, BERCHTOLD ETAL 3,405,951

SAFETY TOE IRON FOR SAFETY SKI BINDINGS 1'7 Sheets-Sheet 17 Filed April 28,

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United States ate ABSTRACT OF THE DISCLOSURE A toe iron for a safety ski binding having a sole holder swingable relative to the ski under the influence of a spring element and said holder being held by the spring element in the normal position in such a way that upon swinging out the sole holder is swung back by the spring element into the normal position, the improvement comprising two swing levers arranged symmetrically to the central longitudinal plane of the ski and operatively coupled to the spring element and sole holder such that the moment arm of the spring element and a sole holder force acting on the swing levers for release are such that after a swinging of the sole holder from the normal position towards either side by a predetermined amount, a restoring moment again acts on said holder which corresponds to the moment which in normal position opposes movement of the sole holder and which does not increase upon the further swinging of the sole holder. Preferably, the predetermined amount approximates 30.

This invention relates to a safety toe iron for safety ski bindings, which toe iron comprises a pivoted member, which is pivotally movable against spring action to release the foot and is adapted to be restored by the spring action from its release position to its normal position.

Safety toe irons of this kind are known. One of these known designs comprises a spring-loaded piston, which is guided in a bore and by a strong coil spring is forced against a flat of the member that is secured to the ski. In another known design, at least one of the members which are pivotally connected to each other is connected by an elastic articulated joint to the associated part of a detent device.

In view of this prior art it is an object of the invention to use a spring system instead of the ball detent included in the known safety toe irons for safety ski bindings so that the pivoted member is also adapted to be restored by spring force from its release position to its normal position. This object should be accomplished in such a :manner that the spring system can be subsequently incorporated in safety toe irons of various designs.

In a safety toe iron of the kind described first hereinbefore, the above object is accomplished by the invention in that the pivoted member is provided with a stop, two levers, which are spring-urged to engage opposite sides of the stop in their normal position, are mounted on the base-plate or another component, relative to which the pivoted member is pivotally movable, and the spring force and the distance from the lever pivot and the point where the stop is engaged are selected so that the torque which opposes an outward pivotal movement beyond pre determined angle of preferably about 30 is equal to the torque which opposes the outward pivotal movement from the initial position. The safety toe iron according to the invention has always a sufiiciently large restoring force and for this reason has a very good shock-absorbing action. In many cases it may be used so as to afford an automatic restoring action.

In a development of the invention, the levers have angled lugs with spherical recesses, which a coil spring, mounted on a guide, is secured with the aid of sphericalhead screws.

The spring system according to the invention may also be used with safety toe irons for safety ski bindings having three parts, which are pivotally movable relative to each other.

In a preferred embodiment, a pivoted member of the toe iron has an elongated hole and when actuated rolls initially to the side and then forwardly by means of rollers, which are in contact with raceways. In a further development of the invention, the spring system may be divided into two individual systems. In this case the two bell-crank levers have no common fulcrum. Such design is realized according to the invention in that each bellcrank lever has a separate pivot and is associated with a coil spring extending in the longitudinal direction of the ski.

The use of the spring system according to the invention is particularly advantageous in conjunction with a safety toe iron having two articulated joints.

The safety toe iron according to the invention can be simplified even to the extent of eliminating the usual pivoted member. This design is characterized in that the bell-crank levers have a toe abutment and a sole lug so that the spring system is directly actuated by the toe of the skiing boot.

The previously known designs comprise helical tension springs, The invention may be realized also with helical comprision springs. In this design, each bell-crank lever has associated with it a separate stop pin and an abutment for a helical compression spring, which is prestressed between said stop pins.

This design may be modified in that each bell-crank lever is mounted on a pivot at the forward end of a baseplate, the bell-crank levers have associated with them a common stop pin, which is mounted on the baseplate, and two helical compression springs are provided, each of which is prestressed between one of the bell-crank levers and a spring abutment mounted on the baseplate.

Various embodiments of the invention will be described hereinafter with reference to the accompanying drawing, in which:

FIG. 1 is a side elevation showing the spring system according to the invention, without toe iron,

FIG. 2 is a top plan view of the arrangement of FIG. 1 with the spring system in position of rest,

FIG. 3 is a top plan view of the arrangement of FIG. 1 with the spring system in actuated position,

FIG. 4 a diagram representing the variation of torque for various spring preloads and deflection angles,

FIG. 5 a side elevation showing a first embodiment of a safety toe iron according to the invention,

FIG. 6 a top plan view of FIG. 5,

FIG. 7 a side elevation showing a second embodiment of the safety toe iron according to the invention,

FIG. 8 a top plan view of FIG. 7,

FIG. 9 a sectional top plan view of FIG. 7,

FIG. 10 a side elevation showing a third embodiment of the safety toe iron according to the invention,

FIG. 11 a sectional top plan view taken on line CD in FIG. 10,

FIG. 12 a sectional top plan view taken on line A-B in FIG. 10,

FIG. 13 a side elevation showing a fourth embodiment of the safety toe iron according to the invention,

FIG. 14 a sectional top plan view of FIG. 13,

FIG. 15 a top plan view of FIG. 13,

FIG. 16 a side elevation showing a fifth embodiment of the safety toe iron according to the invention,

FIG. 17 a sectional top plan view of FIG. 16,

FIG. 18 a side elevation showing a sixth embodiment of the safety toe iron according to the invention,

FIG. 19 a sectional top plan view of FIG. 18,

FIG. 20 a top plan view showing a seventh embodiment of the safety toe iron according to the invention and FIG. 21 a side elevation of FIG. 20,

FIGS. 22. to 24 show various ways in which the spring system according to the invention may be incorporated,

FIG. 25 is a graph for determining the various torques,

FIG. 26 is a graph showing the variation of torque for various spring preloads and deflection angles,

FIG. 27 a graph showing the characteristic curves of the coil springs which are employed,

FIG. 28 a side elevation showing an eighth embodiment of the safety toe iron according to the invention,

FIG. 29 a sectional top plan view of FIG. 28,

FIG. 30 a side elevation showing a ninth embodiment of the safety toe iron according to the invention,

FIG. 31 a sectional top plan view of FIG. 30,

FIG. 32 a sectional top plan view showing a tenth embodiment of the safety toe iron according to the invention,

FIG. 33 a sectional top plan view showing an eleventh embodiment of the safety toe iron according to the invention,

FIG. 34 a side elevation of FIG. 33,

FIG. 35 a sectional top plan view showing a twelfth embodiment of the safety toe iron according to the invention, and

FIG. 36 a side elevation of FIG. 35.

For the convenience of explanation, FIGS. 1 to 4 show the spring system alone, without a safety toe iron with which it may be combined. As is apparent from FIGS. 1 and 2, bell-crank levers 1 and 2 are pivoted to a mounted plate '7 at 3. With the 'aid of spherical-head, countersunk screws 5 and 6, a coil spring 4 is prestressed between the bell-crank levers, which bear under a predetermined torque aXP on the stop pin 8. The angled portion 9 or 10 of each bell-crank lever is formed with a spherical recess for a spherical head, countersunk screws 5 or 6. For the convenience of description, the spring system shown in FIGS. 1 to 3 and comprising parts 1 to 12 will now be generally referred to as spring system 22.

The safety toe iron shown in FIGS. 5 and 6 comprises a base housing 13, which is secured to a ski 16 at 14 and 15. A pivoted member 17 is pivoted to the housing 13 at 21 and comprises a toe abutment 18, a sole lug 19 and an actuating strap 20. The spring system 22 is pivoted to the housing 13 at 23 and with its angled portions 11 and 12 engages the actuating strap 20.

FIGS. 7 to 9 show a safety toe iron having a base housing 24, which is secured to the ski 16 at 25. A base housing 24 has two raceways 26 and 27 and mounts a pin 28. The spring system 22 is mounted at 29. A pivoted member 30 is provided with a rotatably mounted toe abutment 31, a sole lug 32 and two rollers 33 and 34. The member 30 is provided with an elongated hole 35, by which it is mounted on the pin 28 An actuating strap 36 for the spring system 22 is firmly connected to the pivoted member 30.

FIGS. 10 to 12 show another safety toe iron. A baseplate 37 comprises a tapped bushing 33 and a ball detent 39 and is secured to the ski 16 at 40 and 41. The spring system 22 is mounted at 42. A pivoted member 43 is provided with a toe abutment 44, a sole lug 45, an actuating strap 46 and two slots 50 and 51 and by an upright pin 47 is rotatably mounted in the tapped bushing 38. The upright pin 47 is formed in its lower portion with a groove 48 for receiving the ball detent 39 and is further provided with a thrust flange 49. The pin has a milled flat in its upper portion. The two cylindrical sections 53 and 54 fill the bearing. A top plate 55 cooperates 4- with the thrust flange 49 to limit the bearing in an upward direction. I

FIGS. 13 to 15 show another safety toe iron. A base housing 56 is secured to the ski 16 at 57 and 58. The spring system 22 is mounted at 59 and a pivoted member 60 having an actuating strap 61 is mounted at 62. A pivoted member 64 has a toe abutment 65 and a sole lug 66 and is rotatably mounted at 67.

The mode of operation of the spring system and its combination with the different safety toe irons will now be explained:

FIGS. 1 and 2 show the spring system in position of rest. As the two bell-crank levers 1 and 2 are freely rotatably mounted, they are urged by a torque a P against the stop pin 8. When the system has been actuated, as oshown in FIG. 3, by a force P which has opened the system by an angle a, a torque a P will be effective. FIG. 4 shows three curves, which exactly represent the variation of torque for three different spring preloads. It is apparent from curve I that the torque increases slightly until an included angle of about 15 has been reached and at an included angle of about 30 has again the initial value.

rapidly. The data for the curves illustrated in FIG. 4 are as follows:

(I) Prestrain=5 mm.=P 10 k-p. at 0 (M =a -P) (II) Prestrain=6 mm.=P 12 kp. (III) Prestrain=7 mm.=P 14 kp.

When the spring system is applied to a safety toe iron, this means that there is no need for a ball detent and a very good shock absorbing effect is achieved with an exactly adjustable torque or actuating force. An impact in the transverse direction of the ski will result in a response of the spring system but this will immediately return to its initial position. In this case the slight increase in torque up to an angle of about 10 is highly favorable because a sufiiciently strong restoring force is effective in this position. Only if the transverse force is maintained, e.g., during a twisting fall, this will result in a release of the toe because the system will then be sufiiciently opened. Another advantage resides in that the spring system automatically moves a safety toe iron to its operative position after the spring system has been actuated.

In FIGS. 5 and 6 the spring system is combined with a simple safety toe iron having a single articulated joint. In case of a twisting fall, a force P or F is effective so that the spring system 22 is actuated by means of the ac tuating strap 20. The pivoted member 17 can pivotally move in a lateral direction sufiiciently for a release of the toe.

FIGS. 7 to 9 show also a safety toe iron having a single articulated joint, but the gripping pressure is taken up by the rollers 33 and 34 in this case. A force acting in direction P or P will actuate the spring system 22 by means of the actuating strap 36, which is firmly connected to the pivoted member 30. The pivoted member 30 is initially pivotally outwardly moved to the left or right until the raceways 26 and 27 have released the rollers 33 and 34. As the pivoted member is mounted on the pin 28 by means of an elongated hole 35, the pivoted member will then yield forwardly. The angle at which the release is effected is determined by the width of the raceways.

FIGS. 10 to 1-2 show a similar safety toe iron which is also pivotally moved first in a lateral direction and then yields forwardly. This is obtained by a different design. The pivoted member 43 acts through the actuating strap 46 on the spring system 22. A force acting in the direction P or P causes a sufiiciently large pivotal movement of the pivioted member so that a slot 50 or 51 is in registry with the milled flat 52 of the upright pin 47. Thereafter the pivoted member yields forwardly as far as this is permitted by the slot. As the upright pin 47 is rotatably mounted in the tapped bushing 38 and is locked only by the ball detent 39, the pin 47 can continue its rotation when the action of the ball detent 39 has been overcome. This enables a vertical adjustment.

FIGS. 13 to show the use of the spring system with a safety toe iron having two articulated joints. A force in the direction P or P causes the pivoted members 60 and 64 to act through the actuating strap 61 on the spring system 22.

FIGS. 16 and 17 show another example of the spring system according to the invention. In this case, there is no common fulcrum for the two bell-crank levers. The spring system is divided into two individual systems so that two coil springs are required. A baseplate 67 is secured to the ski 16 and is provided with bearings 68 and 69 for bell-crank levers 70 and 71 and with a bearing 72 for a pivoted member 73, which is provided with an actuating strap 74. Different from the spring system 22, coil springs 75 and 76 extend longitudinally of the ski rather than transversely thereto and are mounted at 77 and 78 on the bell-crank levers 70 and 71 and at 79 and 80 on an eccentric pin 81. A stop 82 as well as a bearing 83 for the eccentric pin 81 are also firmly connected to the baseplate 67.

FIGS. 18 and 19 show another embodiment applied to a safety toe iron having two articulated joints. A baseplate 84 has been an upright pin 86 and is secured to the ski 16 at 85. A pivoted member 87 is mounted with the aid of a tapped bushing 88 on the upright pin 86 and has an actuating pin 89. A second pivoted member 90 is mounted at 91 on the pivoted member 87 and is provided at 92 with a bearing for the spring system 22. A force acting in direction P or P causes the actuating pin 89 to ac tuate the spring system.

FIGS. and 21 show another embodiment, in which the usual pivoted member is omitted and the spring system 22 is directly effective. Bell-crank levers 93 and 94 are provided with a toe abutment 95 and a sole lug 96. In this arrangement the spring system is directly actuated by the toe of the skiing boot.

FIGS. 22, 23 and 24 show diflerent ways in which the spring system 22 may the arranged. These arrangemensts are shown alone, for convenience of explanation.

FIG. 22 shows the spring system 22 and a pivoted member 97 having bearings 103, which are in registry. This means that an actuation of the spring system does not result in a relative movement between an actuating strap 98 of the pivoted member 97 and the bell-crank lever 1 and 2.

FIG. 23 shows the spring system 22 and a pivoted member 99 wih offset bearings 104 and 105'. In this case, an actuation of the spring system results in a relative movement between an actuating strap 100 of the pivoted member 99 and the bell-crank levers 1 and 2.

FIG. 24 shows an arrangement like that of FIG. 23 but with an actuating strap 102, which is displaceable in the direction of the arrow against a spring force. As a result, an actuation of the spring system caused by the relative movement of the actuating strap 102 and the bell-crank 1 or 2 causes a release of the bell-crank lever 1 or 2 after a small pivotal movement so that the pivoted member 101 can then be freely pivotally moved in an outward direction. When the pivoted member is being restored, the actuating strap 102 snaps back between the bell-crank levers 1 and 2 of the spring system 22.

FIG. shows how the various torques are determined. The values are plotted for deflection angles differing by increments of 5. It is apparent that after a deflection by an angle of, e.g., 20 the lever arm a has been reduced from 12 millimeters to 8 millimeters and the spring has been extended by 3.5 millimeters.

FIG. 27 shows the characteristics curve (force-deflection curve) of the coil spring which is employed. When prestrained by 5 mm., the spring applies a force of 10 kiloponds. After a deflection by an angle of 20, the

spring has been further deflected by 3.5 millimeters so that a spring force of about 17.1 kiloponds is now eifective. At a deflection angle of 20, the torque is thus equal to 0.8 17.1=13.68 or approximately 13.7 kiloponds, as is apparent from FIG. 26. The variation of torque during a deflection through an angle of 40 is shown in three curves for a spring which is prestrained by 5 millimeters, 6 millimeters and 7 millimeters, respectively. The data for the curves illustrated in FIG. 26 are asfollows.

(I) Prestrain 5 mm.:

Cm.kg. 0 1.2 10 12.0 5 1.1 12 13.2 10 1.0 13.5 13.5 15 0.9 l5.2 13.7 20 0.S 17.1 13.7 25 0.7 18.8 13.2 30 0.6 19.6 11.8 35 0.5 20.8 10.4 40 0.4 21.5 8.6

(II) Prestrain 6 mm.:

0 1.2X12 14.4 5 1.1 14 15.4 10 1.0X15.6 15.6 15 0.9 17 15.3 20 0.8 l8.8 15.0 25 0.7 20.4 14.3 30 0.6X21.6 13.0 35 0.5 22.4 11.2 40 0.4 23.2 9.3

(III) Prestrain 7 mm.:

FIGS. 28 and 29 show another embodiment of the spring system where the helical tension springs are replaced by a helical compression spring. The conditions for this embodiment are the same as for the spring system 22. The preset initial torque (releasing force) should be attained after a deflection by an angle which is favorable and necessary for safety toe irons. A baseplate 106 having an upright pin 107 is secured to the ski 16 at 108. A pivoted member 109 having an actuating strap 110 is pivoted to the upright pin 107. Bell-crank levers 111 and 113 are pivoted to the baseplate 106 at 112 and 114, respectively. Stop pins 115 and 116 are associated with the bell-crank levers 111 and 113, respectively. A compression spring 117 is pivotally mounted between the bell-crank levers at 118 and 119 and held under initial stress. A force P or P causes an actuation of the spring system by the actuating strap 110.

FIGS. 30 and 31 show another embodiment of the spring system, which diflers from that of FIGS. 28 and 29 in that two helical compression springs are used. A baseplate 120 having an upright pin 121 is secured to the ski 16 at 122. A pivoted member 123 provided with an actuating strap 124 is pivoted on the upright pin 121. Bell-crank levers 125 and 127 are pivoted to the baseplate 120 at 126 and 128, respectively. The two bellcrank levers cooperate with a stop pin 129, which is firmly connected to the baseplate 120, just as the spring abutment 130. The helical compression spring is held under initial stress between the bell-crank lever 125 and the spring abutment 130 at 132 and 133, respectively. The helical compression spring 134 is also held under initial stress between the bell-crank lever 127 and the 

